1. Technical Field
This invention relates generally to a method and apparatus for attaching a circuit component to a printed circuit board and, in particular, to a method and apparatus for quickly and reliably attaching a component, such as a gate array device, that may have a relatively large number of pin-type contacts to a printed circuit board.
2. Description of the Related Art
When first developed, components such as integrated circuits were relatively simple devices with few input/output requirements. Thus, packaging was generally accomplished by such simple configurations as dual in-line packages with, for example, only fourteen pin-type contacts extending therefrom. However, with the development of increasingly sophisticated electronic circuits and, correspondingly, higher component density integrated circuits, the physical packaging of integrated circuits advanced to larger dual in-line packages with increased numbers of pin-type contacts disposed about the periphery of the package.
More recently, integrated circuits have attained a sophistication and density that requires more pin-type contacts than can reasonably be distributed about the periphery of an integrated circuit. Accordingly, gate array devices have been developed that can have 160 or more pin-type contacts. Typically, gate array devices have their pin-type contacts arranged in a generally rectangular pattern extending from a rear or mounting surface of the integrated circuit. These pin-type contacts are mated with corresponding plated-through openings on a printed circuit board and soldered into place.
It should be appreciated that manually soldering such a large number of pin-type contacts is a time consuming process, readily subject to errors and/or unacceptable joints. Standard, automated wave soldering techniques or solder preform techniques are readily applicable to gate array devices, but are typically available only for production printed circuit boards. That is to say, during the development of a printed circuit board, production techniques are typically not used, since the development-type printed circuit board is subject to numerous design changes. Rather, during development, it is preferable that the printed circuit board be readily alterable, such as, by removing and replacing electrical devices which may be socket mounted thereon.
Therefore, it is desirable that a method and apparatus be developed to accurately and quickly mount components such as gate array devices on printed circuit boards while minimizing time consuming manual tasks. Further, it is preferable that this technique also be readily utilized in production-type environments.
Additionally, the increased component density of integrated circuits has resulted in the need for a greater magnitude of heat being dissipated from the integrated circuit. Typical dual in-line packages have their lower or mounting surface free for intimate mating with a heat sink. Thus, heat is readily dissipated through the mounting surface and into an appropriately sized heat sink. However, components such as gate array devices have their mounting surface substantially occupied by pin-type contacts and cannot simply be mounted on a conventional, electrically conductive heat sink.
The present invention is directed to overcoming or minimizing one or more of the problems discussed above.